Description
Emerson CSI 3125 A3125/022-020 Product Description
Product Overview
Emerson CSI 3125 A3125/022-020 is a Bearing-Vibration Monitor designed for continuous monitoring of rotating machinery vibration. The exact A3125/022-020 configuration is specified for vibration velocity measurement, with a sensitivity of 100 mV/in/s. Emerson documentation identifies the product as the AMS 3125 Bearing-Vibration Monitor.
The CSI 3125 is intended for smaller rotating-machine applications where a compact, dedicated vibration monitor is required. Typical applications include steam turbines, gas turbines, water turbines, compressors, pumps and fans.
Technical Specifications
| Parameter | Specification |
|---|---|
| Manufacturer | Emerson / CSI |
| Model | CSI 3125 |
| Part Number | A3125/022-020 |
| Product Type | Bearing-Vibration Monitor |
| Measurement | Vibration Velocity |
| Sensitivity | 100 mV/in/s |
| Supply Voltage | +24 VDC nominal |
| Permissible Supply | +18 to +31.2 VDC |
| Power Consumption | Max. 6 W |
| Buffered Outputs | 2 × ±4 VDC |
| Buffered Output Accuracy | ±2.5% |
| Current Outputs | 2 × 0/4–20 mA |
| Current Output | Galvanically isolated |
| Maximum Burden | 500 Ω |
| Relay Outputs | 5 × make contacts |
| Relay Voltage | 48 VDC max. |
| Relay Current | 1 A max. |
| Relay Contact Power | 50 W max. |
| Mounting | Wall mount |
| Enclosure Material | Non-corroding aluminum |
| Approx. Weight | 1.3 kg |
| Typical Application | Rotating machinery vibration monitoring |
The Emerson specification sheet confirms the +24 VDC supply, two buffered outputs, two isolated 0/4–20 mA outputs and five relay outputs.
Main Features and Advantages
Vibration Velocity Monitoring
The A3125/022-020 version is specifically configured for vibration velocity, making it suitable for monitoring overall mechanical vibration on rotating equipment and bearing-related machinery. Emerson distinguishes it from A3125/022-010, which is the acceleration version.
Dual Analog Outputs
The monitor provides two galvanically isolated 0/4–20 mA outputs, allowing vibration measurements to be transmitted to a PLC, DCS, SCADA system or plant monitoring system. The outputs can drive loads up to 500 Ω.
CSI3125
Buffered Vibration Signal Outputs
Two buffered outputs provide ±4 VDC signals, allowing the original vibration measurement to be made available to external monitoring or analysis equipment without interfering with the primary measurement circuit.
Five Relay Outputs
The CSI 3125 provides five make-contact relay outputs. These can be used for alarm, shutdown, trip or equipment-status functions. Each relay is rated up to 48 VDC, 1 A and 50 W.
Compact Industrial Construction
The unit uses a non-corroding aluminum enclosure and wall-mount installation, making it suitable for installation close to monitored machinery or within an instrumentation cabinet. Emerson specifies an approximate weight of 1.3 kg.
Continuous Machinery Protection
By continuously monitoring vibration and providing configurable analog and relay outputs, the CSI 3125 can provide early warning of abnormal mechanical conditions and interface directly with plant protection or control systems.
Application Fields
Steam Turbines
The CSI 3125 can monitor vibration associated with turbine bearings and rotating components, providing analog vibration information and alarm/trip outputs.
Gas and Water Turbines
The monitor is suitable for smaller turbine installations where continuous bearing-vibration monitoring is required.
Compressors
Abnormal vibration is an important indicator of mechanical problems in compressors. The CSI 3125 can provide continuous monitoring and relay-based alarm functions.
Pumps
The monitor can be applied to critical industrial pumps to identify developing mechanical problems such as imbalance, misalignment or bearing deterioration.
Fans and Blowers
For industrial fans and blowers, vibration monitoring can help identify mechanical degradation before it develops into a major equipment failure.
Related Products
- Emerson CSI 3125 A3125/022-010 — CSI 3125 version configured for vibration acceleration, 100 mV/g, 40 g.
- Emerson A6110 — Shaft relative-vibration monitoring equipment for rotating machinery.
- Emerson A6120 — Machinery monitoring equipment used in rotating-equipment protection systems.
- Emerson A6210 — Thrust-position monitor for turbines, compressors and other rotating equipment.
- Emerson A6220 — Machinery health monitoring equipment.
- Emerson A6500 — Machinery protection and monitoring platform.
